Repeater devices that re-transmit signals in telecommunications systems may experience signal distortion resulting from a run-around channel and/or a ring-around channel. A run-around channel may include a channel used by a coverage antenna of a repeater that includes one or more frequencies that can be received by the donor antenna. A ring-around channel may include a channel used by a donor antenna of a repeater that includes one or more frequencies that can be received by the coverage antenna. A run-around channel or ring-around channel can cause a signal transmitted by a first antenna of a repeater, such as a coverage antenna, to be recovered by a second antenna of the repeater, such as a repeater antenna. A delayed version of the recovered signal (also referred to as a round-around signal or ring-around signal) can be erroneously retransmitted by the first antenna. For a repeater having a gain that exceeds the isolation of the antennas, erroneously retransmitting the signal can cause the repeater to clip signals (e.g., overshoot or undershoot scenarios) and/or to oscillate.
Previous solutions for addressing distortion resulting from a run-around channel and/or a ring-around channel may involve using adaptive echo cancellation filters. Adaptive echo cancellation filters may be used to produce error signals that mimic a round-around signal or ring-around signal. Such solutions may not be able to reduce distortion caused by round-around signals or ring-around signals having a channel transfer function that changes rapidly. For example, in-train repeaters, motorway repeaters, and other mobile repeaters may experience distortion from round-around signals or ring-around signals having a channel transfer function that changes rapidly. For round-around signal or ring-around signal having a channel transfer function that changes rapidly, an adaptive echo cancellation system may be unable to cancel the round-around signal or ring-around signal on a run time basis, thereby causing the repeater to clip and/or oscillate.